Energy crisis: why bacteria can't build complex cells: Mitochondria, our cells' power sources, have their own genome that's specialized for energy production. A new paper argues that this extra DNA was key to letting our genomes (and those of other eukaryotes) get big and complex.

Heavy star gives exotic matter theories the heave-ho: New measurements show that astronomers have found the heaviest neutron star currently known. Tipping the scales at nearly two solar masses, it greatly constrains the nature of the materials that can make up a neutron star.

Galaxy Zoo shows how well crowdsourced citizen science works: What do you do when you have a massive database of images, and computers can't perform the scientific analysis you need done? When the people behind the Zooniverse faced that problem, they crowdsourced it to a bunch of citizen scientists who proved adept at both the task at hand and spotting oddities that had escaped professional astronomers.